Sir Adrian will be responsible for overseeing how the UK intelligence agencies operate under the new Investigatory Powers Bill, which governs the agencies' use of investigatory powers and authorisations. He will oversee the work of Judicial Commissioners, who will approve all agency warrants.

The Investigatory Powers Bill received Royal Assent on 29 November 2016. The legislation brings together and updates existing powers while radically overhauling how they are authorised and overseen. It also creates one new power: the introduction of Internet Connection Records, which will be accessible by law enforcement and the intelligence agencies to disrupt terrorist attacks and prosecute suspects. The Bill was introduced to the House of Commons by the then Home Secretary, the Rt Hon Theresa May MP, on 1 March 2016.

David Anderson's review of bulk powers, which critically appraised the need for bulk capabilities, considering whether the same result could have been achieved through alternative investigative methods, was published by the Home Office on 19 August 2016.